Constant velocity universal joints are used in the wheel drive axles of front wheel drive automobiles and four-wheel drive automobiles; these joints are well known to those skilled in the art and are described, e.g., in U.S. Pat. Nos. 4,177,654, 4,300,651, 4,476,950, and 4,634,402, the disclosure of each of which is hereby incorporated by reference into this specification.
The constant velocity universal joint often are damaged during use. However, because of the relatively high cost of the precision machined components in such joints, the complete replacement of the joint is very expensive.
U.S. Pat. No. 4,593,444 of Kavthekar disclosed a machine for manufacturing constant velocity universal joints. The Kavthekar machine requires the use of a plurality of machining stations (and, thus, a plurality of tools). Furthermore, because the Kavthekar machine is designed for the original manufacturing of such joints, it relies upon the keyway of the original blank for positioning a workpiece in the machine. Furthermore, the Kavthekar machine does not contain means to move its grinding spindle in a vertical direction, or means to stop and lock its swing arm in a precise angular position relative to the axis of the grinding spindle; thus, this machine cannot be used to effectively regrind a Cross Groove style or a Plunge style constant velocity joint, and it cannot be used to grind the ball openings of the hardened cage. Furthermore, the Kavthekar machine does not contain means for calibrating the position of any given tool in relationship to the center of rotation in order to insure that precise dimensions are being machined.
It is an object of this invention to provide a system for regrinding a variety of worn constant velocity joints to within manufacturers' original tolerances or better, wherein the original bearing balls are replaced by oversized bearing balls of a common size for a particular type and size constant velocity joint.
It is another object of this invention to provide a system for regrinding the individual components of constant velocity universal joints which ensures precision grinding by the cooperative movement of a workpiece table and a compound grinder table through a predetermined and controlled pattern of positions without interruption of the process for the purpose of monitoring the dimensions of the component being ground.
It is yet another object of this invention to provide a system which regrinds worn or damaged constant velocity universal joints to consistent, precise, and improved tolerances between the bearing balls and the inner and outer races.
It is yet another object of the invention to provide a grinding machine with a novel arrangement of a workpiece holder and a tool holder which is capable of rotating various types and sizes of constant velocity universal joints through predetermined patterns of movements to accomplish precision grinding of various individual components.
It is yet another object of this invention to provide a machine which automatically performs the operations necessary to accomplish precision regrinding of the individual components of various types and sizes of constant velocity universal joints.
It is yet another object of this invention to provide a comprehensive database and catalog for the purpose of identifying constant velocity universal joints, combined with the appropriate information and dimensional locations for automatic positioning of all axes of motion required for the regrinding process.
It is yet another object of this invention to provide a system for grinding one or more of the components of constant velocity universal joints which is comprised of means for aligning the outer housing and/or the inner race component of a constant velocity joint within a workpiece holder attached to said machine.
It is yet another object of this invention to provide a machine for grinding one or more components of constant velocity universal joints which is comprised of a novel tool bit.
It is yet another object of this invention to provide a novel cooling system for cooling the tool bit and workpiece used in the grinding machine.
It is yet another object of this invention to provide a system for grinding constant velocity universal joints which is comprised of an alignment means for aligning the centerline of the workpiece holder of such machine with the centerline of the grinding spindle of such machine.
It is yet another object of this invention to provide a process for grinding one or more of the components of constant velocity universal joints in which various motions of the grinding machine are controlled by a computer program.